Examining the Impact of Regular Aspirin Use and PIK3CA Mutations on Survival in Stage 2 Colon Cancer.

Data suggest aspirin improves survival in CRC harbouring PIK3CA mutations. The impact of aspirin is thought predominantly to be via an anti-inflammatory effect.,To explore the effect of aspirin use on survival in a real world cohort of Stage 2 colon cancer (CC) patients.,A prospective CRC database identified patients diagnosed with stage 2 CC between 2000 and 2011. PIK3CA mutation status was determined by next generation sequencing. Neutrophil-Lymphocyte ratio (NLR) greater than 5 at diagnosis represented systemic inflammation. Chart review was used to record regular aspirin use at diagnosis. Clinico-pathological features and survival data were available. Survival analyses utilised the Cox proportional hazards method.,Of 488 patients with stage 2 CC, 95 patients were aspirin users and 70 patients had PIK3CA mutations. Aspirin users were more likely to be older (median: 76.4 years versus 68.3 years, p < 0.001), to be less fit (American Society of Anaesthetists Score 3-4: 58% versus 31%, p < 0.001), and to have systemic inflammation (NLR>5: 39% versus 27%, p = 0.027). Regular aspirin use did not significantly improve recurrence free survival: In the PIK3CA mutated group, there was a trend towards improved recurrence free survival (HR 0.45, p = 0.42).,Our study did not demonstrate a significant survival advantage from aspirin use in Stage 2 PIK3CA mutated CC. The 'real world' nature of our cohort and the subsequent uncontrolled differences in age and fitness in aspirin users are likely to have contributed to this result. Defining the true impact of aspirin in CRC requires prospective randomised clinical trials.